Design and resonant frequency calculation of rectangular microstrip antennas

This study introduces an original theoretical approach for rectangular microstrip antennas analysis and design. The purpose method consists in the coupling between artificial neural networks tool applied to the analysis of rectangular antennas and a tabu search for the optimization. A neural network acting as database will allow to reduce strongly the computation time. This method will be illustrated in four examples. Copyright © 2010 John Wiley & Sons, Ltd.     

基于主成分分析法和自适应神经模糊推理系统的电力负荷预测

提出了一种基于主成分分析法与自适应神经模糊推理相结合的电力系统负荷预测方法，通过对影响电力负荷的相关因素进行主成分分析，减少自适应神经模糊推理系统的输入量，可以提高系统预测的效率。算例表明所提出方法是有效的和可行的。     

基于LabVIEW的天线方向图测试系统设计

针对传统的天线方向图测量方法效率低、精度差的缺点,基于LabVIEW软件平台开发了1套天线方向图自动测试系统.该系统通过GPIB总线实现对测试仪器的控制,在信号录取、角度录取、数据处理、方向图绘制方面实现了完全自动化,具有精度高、测量速度快、性能稳定的特点.     

High‐speed directional relaying using adaptive neuro‐fuzzy inference system and fundamental component of currents

This paper proposes an adaptive neuro‐fuzzy approach for fault direction estimation in sectional transmission lines. The ANFIS (adaptive neuro‐fuzzy inference system) network is designed by selecting different input and output member functions and rules for training and testing of fault cases. The fundamental component of current obtained from three‐phase current employing discrete Fourier transform (DFT) is given as input to the ANFIS module. The trained ANFIS module is then tested for detecting the fault direction. The relay is located at middle section‐2, which is considered as the primary section to be protected. It takes section‐1 as reverse section and section‐3 as forward section. This method is not affected by the variation of fault type, fault inception angle, fault location, and fault resistance. The biggest advantage of the ANFIS method is that it can detect the fault direction within 1 ms in almost all cases, which is much less than the implemented distance relaying scheme. The second advantage of the method is that it takes less number of training samples to detect the direction accurately as compared to other training algorithms like ANN, SVM, etc. The third advantage of the proposed scheme is that it offers protection to 99% of line length in all the three sections. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

在相同相对介电常数情况下不同厚度的微带贴片天线设计与仿真验证

微带贴片天线的基板材料的相对介电常数和介质板厚度是影响天线性能的重要因素.为了验证在相同相对介电常数的情况下,改变介质基板的不同的厚度时微带矩形贴片天线的阻抗带宽的变化,通过HFSS软件设计和仿真了工作频率为1.95 GHz的4个矩形微带贴片天线,相对介电常数均为2.2,介质基板厚度分别设计为0.8、1.6、2.4、3.2 mm,比较其各自的S参数、方向图,通过仿真结果验证了相关文献所述的对于在给定的频率下,选用相同的基板材料时,厚度增大时阻抗带宽会变大的说法.     

Optimal slip ratio estimator for traction control system of electric vehicle based on fuzzy inference

In this paper we propose an optimal slip ratio estimation method based on fuzzy inference. One of the major advantages of electric vehicles is the quick and precise torque response of the electric motor, which realizes a novel traction control system. To prevent skidding, optimal slip ratio control has been successfully developed. It maintains the slip ratio at the optimum value that gives the maximum driving force. The remaining problem is how to generate the optimal slip ratio command sent to the controller. First we show that effective estimation of the optimal slip ratio is difficult to perform by the simple gradient method, which is a well‐known optimization method. But various experimentally obtained data can be easily incorporated into fuzzy inference, and therefore its estimation performance can be easily improved by the accumulation of human experience. This is a major advantage in the nonlinear estimation of real road‐tire characteristics. The effectiveness of the proposed estimation and control methods is confirmed by numerical simulation. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 56–63, 2001     

A method for the conservative evaluation of safe space around systems with aperture antennas

In this work, a novel method is presented, with which the safe space around aperture antennas can be assessed. The basis of this new approach is the approximate similarity of the contours between uniformly and non-uniformly illuminated apertures. The isoparametric contours that result from numerical calculations have to be replaced by envelope contours that fully enclose them, in order to avoid radio frequency hazards. These envelopes were approximated with analytical formulas. Various examples of different apertures are presented, which demonstrate the mode of application and the validity of our method.     

左心室辅助装置控制系统的建模与仿真

提出一种采用无刷直流电动机设计的左心室辅助装置,通过对自然心脏的搏动规律的分析进行建模仿真.先采用传统PID控制,获得速度环的偏差、偏差变化率以及转速的数据,然后将这些数据在MATLAB的自适应神经模糊工具箱进行训练来设计模糊控制器.结果表明:训练后得到的模糊控制器要比传统PID控制器设计简单,控制响应速度快,鲁棒性好.     

A review of stabilization methods for DCMG with CPL, the role of bandwidth limits and droop control

DC microgrids (DCMGs) integrate and coordinate various DC distribution generation units including various renewable energy sources and battery storage systems, and have been used in satellites, the International Space Station, telecom power stations, computer power supplies, electric aircraft, and electric ships. However, the presence of constant power loads (CPLs) can cause instability in DCMGs. Thus, this paper reviews the stabilization techniques that can resolve instability caused by CPLs, as well as various parameters of CPLs, such as bandwidth, and the frequency of the CPLs that can stabilize the DCMGs. It also discusses recent trends and future work in finding stability limits using the parameters of CPLs. It should be useful for directing research towards appropriate mathematical and experimental approaches for the stability of DCMGs with CPLs.     

自适应和模糊推理结合的故障分类新方法

输电线上许多类型的故障伴随低阻抗故障和高阻抗故障发生,传统的保护方法不能正确地检测和分类.提出了一种基于自适应网络的模糊推理机制(ANFIS)对低阻抗故障和高阻抗故障进行故障检测和分类的新算法.算法的性能已得到韩国典型的154 kV输电线系统在各种故障条件下的测试.测试结果表明ANFIS能在半个周期内准确地检测故障和区分故障类型(包括低阻抗故障和高阻抗故障).     

机载电子设备故障诊断专家系统的设计与实现

针对航空机载电子设备故障知识日益膨胀导致的故障诊断系统效率低下、难以快速有效地进行电子装备维护的问题,提出了一种新的、基于专家系统的机载电子设备故障诊断系统。分析了专家系统的原理和结构,研究了一般产生式规则与模糊产生式规则相结合的知识表示方法及精确推理与模糊推理相结合、基于规则推理、案例推理、模型推理及混合推理的推理机制。以Delphi7．0和Oracle9i为开发环境,开发了该专家系统。系统能快速分析故障现象,列出可能的故障原因,输出故障报告,提供故障处理指导。研究表明,新系统具有更高的效率、并且诊断结论也更可靠、可维护性也更好,在实际的航空机务维护工作中取得了良好的效果。     

电动汽车充放电系统的单相三电平整流器研究

通过对电动汽车蓄电池充放电系统进行的研究,提出了一种单相三电平整流器,首先分析了其电路结构及原理,建立了基于开关函数的数学模型。然后,针对蓄电池充放电系统对直流侧电压控制要求稳定程度高的特点,采用自适应神经网络模糊控制算法对直流侧电压进行跟踪控制。MATLAB仿真结果验证了它的有效性,克服了采用传统PI调节动态性差和抗负载扰动能力差的问题。     

继电保护整定计算专家系统在四川电网的应用

介绍了 110～ 5 0 0kV电网零序电流保护、相间距离保护、接地距离保护整定计算专家系统在四川电网的实际应用情况及其产生的经济效益和社会效益。实际应用表明 ,该专家系统具有较高的实用价值和推广应用价值     

Design and allocation of power system stabilizers using the particle swarm optimization technique for an interconnected power system

In this paper, three particle swarm optimization (PSO) based power system stabilizers (PSSs) are developed for three power systems. The system under study here is a power pool consisting of 3 power systems. System I represents the Egyptian power system, system II represents the Jordan and Syrian power systems, and system III for the Libyan power system, which are originally self standing and completely independent systems. As a matter of fact each of them should equipped with its own PSS. For this reason this work is started by designing an optimum power stabilizer for each of them standing alone. After which, the developed PSSs are firstly installed one at a time. Then the three PSSs are installed together in the interconnected power system and their effect on its dynamic performance is studied.As a test for stabilization efficiency, the detailed power system model is subjected to a forced outage of a 600-MW generator, which is the biggest unit in the pool, when it is fully loaded. This outage results in loosing of about 3% of the spinning capacity of system I and about 2% of the spinning capacity of the whole interconnected system. The obtained results show an improvement in the power pool performance accompanied with an improvement in the inter-area oscillation.     

Determination of the optimal DR capacity for a commercial building with chiller system and energy storage system

Demand response (DR ), which is used to shave the peak demand for securing supply reliability in a power system, is one of the promising constitutions for the end users. In a commercial building (COB ), the most popular adjustable DR resource (DRR ) is the chiller system. More specifically, its power consumption can be reduced by thermal mass control (precooling) in a specified DR duration. On the other hand, installation of energy storage systems (ESSs ) is going on at an accelerated pace because of its high economic efficiency. ESSs have been used for peak‐shift operation under the time‐of‐use (TOU ) tariff. However, ESS can be also used as an attractive DRR because it can reduce the net load by discharging the ESS for a specified DR duration. Based on this background, this paper presents a method for determining the optimal DR capacity in a COB with a chiller system and ESS . In the proposed scheme, the optimal DR capacity (kW ) can be determined so that the total expected cost of a COB becomes minimum by using the chiller system and ESS while avoiding the DR penalty threat adopted in the Korean DR market. Uncertainty in the ambient temperature, the amount of reduction, and DR durations are considered as the scenarios. The estimation and economic evaluation of the proposed scheme is ascertained through case studies. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

对空警戒雷达自动测试系统的设计与实现

对空警戒雷达在探测空中飞行目标,提供空中预警情报系统中发挥着重要作用。目前对对空警戒雷达的测试,主要采用传统的手动测量方法,工效低,且雷达多项功能参数无法测试。针对对空警戒雷达的测试保障现状,本文提出了基于虚拟仪器技术的对空警戒雷达自动测试系统的集成方案,详细描述了系统的功能和总体结构,提出了自动测试的过程控制策略,重点讨论了测试系统软硬件设计方案;实用证明,该系统精度满足要求,能完成预定测试工作,运行性能良好。     

感应电机速度和电阻自适应辨识的LMI方法(英文)

该文研究了一种感应电机无速度传感器模型参考自适应系统(model reference adaptive system,MRAS),提出一种新型的基于自适应磁链观测器的常数增益速度辨识方法。首先,运用李亚普诺夫(Lyapunov)稳定性理论设计出自适应磁链观测器及速度估算方法,通过MATLAB中的线性矩阵不等式(linear matrix inequality,LMI)工具箱求解线性矩阵不等式获得磁链观测器的增益矩阵,保证了此磁链观测器的稳定性,同时也克服了运用极点配置方法带来不稳定区域的问题。该文还研究了基于自适应观测器的电阻辨识问题。基于给出的自适应磁链估计方法,设计了感应电机无速度传感器直接转矩控制系统,并进行了MATLAB仿真和实验,结果表明,提出的无速度传感器速度方法在全速范围内具有很好的动态和静态性能。     

蓄电池电驱动系统的匹配和优化

电驱动系统是电动自行车的关键，而蓄电池是电驱动系统的关键部件。指出，电驱动系统各部件之间的匹配和优化对于提高电动自行车的质量有着重要作用和意义。着重介绍了蓄电池和充电器之间的匹配和优化以及蓄电池放电深度与循环寿命之间的关系。     

电厂信息系统的规划与设计

随着信息技术在过程自动控制和生产经营管理等方面的广泛应用，使过程与管理信息成为全面反映电厂生产、经营和管理的一个重要窗口。如何利用这些信息为生产、经营和管理服务是电厂信息化的重要内容。阐述了电厂信息化的重点是对构成发电系统诸多设备的相关信息进行采集、存储、加工和利用，分析了国内在电厂信息系统建设方面与发达国家的差距，提出了电厂信息系统应该包括厂级监控信息系统(SIS)和管理信息系统(MIS)，应用系统和计算机网络不应根据专业进行划分。论述了信息系统的规划设计与控制系统设计和企业信息规划之间的区别，在给出电厂信息系统模型的基础上，提出了电厂信息系统中应包括的内容，指出电厂信息系统的规划设计需各专业的协调与配合，并根据各阶段的实际需要进行建设。     

A ubiquitous Web-based dispatcher information system for effective monitoring and analysis of the electricity transmission grid

Effective electricity grid management and planning necessitates widespread installation of convenient data acquisition modules to obtain the relevant grid data in a timely manner. In this paper, we describe a ubiquitous Web-based dispatcher information system deployed on the Turkish electricity transmission grid. This large-scale system is utilized by the transmission system operator to effectively monitor the transmission grid and to analyze and summarize the gathered data automatically, in order to take proper short-term and long-term operational decisions. The system has the additional facilities to produce load forecasts and track long-term investment plans on the electricity grid. The architecture of the implemented system is described in details together with the demonstration of sample significant analysis and forecast results obtained from the system.